We present the phase locking of an array of index-guided tapered laser diodes. An external cavity based on the self-imaging Talbot effect has been built. A volume Bragg grating is used as the output coupler to stabilize and narrow the spectrum at 976 nm. A power of 1.7 W is achieved in the in-phase single main lobe mode with a high visibility. We have checked that each emitter is locked to the Bragg wavelength with a 100 pm spectrum linewidth. The experimental results compare well with numerical simulations performed with two-dimensional wide-angle finite difference beam propagation method

The propagation of defect networks in failed 980 nm emitting high‐power diode lasers is analyzed. This is accomplished ex post facto by electron‐beam based techniques applied without device preparation and in situ by thermographic microscopy with 1 µs time resolution. Moreover, an iterative model is established, which allows for describing both the shape of the observed defect networks as well as the kinetics of their spread. This concerted approach allows the clear assignment of starting points of extended defect systems as well as analysis of their evolution kinetics. Eventually this knowledge may help in making devices more resistive against defect creation and extension.

Single-pulse tests of the catastrophic optical damage (COD) are performed for three batches of diode lasers with different gain-regions. The tests involve in situ inspection of front, rear, and side of the devices by a thermocamera. Devices with an Al-containing gain-region show COD at the front facet, as expected for strong facet heating via surface recombination and reabsorption of laser light. In contrast, Al-free devices with low surface recombination rates tend to fail at the rear facet, pointing to a different heating scenario. The high carrier density at the rear facet favors heating and COD via Auger recombination processes.